diff --git a/src/main/java/com/ffii/tsms/config/WebConfig.java b/src/main/java/com/ffii/tsms/config/WebConfig.java
index bf3c622..480cc88 100644
--- a/src/main/java/com/ffii/tsms/config/WebConfig.java
+++ b/src/main/java/com/ffii/tsms/config/WebConfig.java
@@ -2,6 +2,8 @@ package com.ffii.tsms.config;
 
 import org.springframework.context.annotation.Bean;
 import org.springframework.context.annotation.Configuration;
+import org.springframework.http.MediaType;
+import org.springframework.web.servlet.config.annotation.ContentNegotiationConfigurer;
 import org.springframework.web.servlet.config.annotation.CorsRegistry;
 import org.springframework.web.servlet.config.annotation.EnableWebMvc;
 import org.springframework.web.servlet.config.annotation.WebMvcConfigurer;
@@ -26,4 +28,9 @@ public class WebConfig implements WebMvcConfigurer {
     return new InternalResourceViewResolver();
   }
 
+  @Override
+  public void configureContentNegotiation(ContentNegotiationConfigurer configurer) {
+    configurer.defaultContentType(MediaType.APPLICATION_JSON);
+  }
+
 }